FXP611 Flexible PCB Antenna with Cable Application Note

Transcription

1 FXP611 Flexible PCB Antenna with Cable Applicatin Nte APN /A/MB Page 1 f 6

2 1. BASICS A Flexible PCB antenna with cable is a very flexible, lw prfile, highly reliable, and ecnmical slutin widely used in the wireless industry. Usually cnsisting f plyimide flexible PCB (plyimide), a trace is printed n the substrate t get the desired antenna tplgy. Varius antenna types such as mnples, diples, and printed F antennas can be made. This design applicatin nte is intended t help the antenna integratr understand the relevant parameters affecting the antenna perfrmance. Taglas recmmends that the integratr strictly fllw the guidelines in this applicatin nte. Upn yur device prttype cmpletin, Taglas can prvide further ptimizatin by custm tuning and testing service f the antenna in yur device. (see Sectin 15 f this dcument fr further inf n Tuning) 2. APPLICATIONS A Flexible PCB antenna with cable is suitable fr mbile applicatins where internal antennas are required, but nt much space r vlume is available. It is ideally affixed t the plastic husing f a device directly by duble-sided adhesive. Taglas Flexible PCB antennas cme in single-band r multi-band slutins starting frm 450MHz up t 6 GHz. APN /A/MB Page 2 f 6

3 3. SIZE The larger the antenna surface area (r vlume), in general the higher the perfrmance in terms f gain and radiatin characteristics. 4. SHAPE AND THICKNESS A Flexible antenna can be made int any 2D shape fr ease f fit int a prduct. Flexible PCB antennas are super lw prfile (0.5mm). 5. GROUND PLANE EFFECTS In general there shuld be 10mm f minimum clearance frm the main grund-plane t achieve adequate antenna efficiency. Clse prximity t the grund plane can degrade the antenna perfrmance. APN /A/MB Page 3 f 6

4 6. POLARIZATION GPS patch antennas are mst widely used fr GPS receiver applicatins because they are circularly plarized antennas. The advantage is that patch antennas can be made t be circularly plarized, which matches mre efficiently with the circularly plarized radiatin transmitted frm the GPS satellites. The disadvantages f the patch antennas can be very critical smetimes because they are very directinal and very sensitive t device rientatin. The FXP611 is linear plarized antenna, but it pses an mnidirectinal attribute which makes it less sensitive t the rientatin. The antenna can be munted vertically r hrizntally in the device. 7. ADVANTAGES f Flexible antennas with cable Adheres directly t inner shell f plastic husing f device N space needed n main bard f device Extremely lw prfile Design Flexibility size, shape, cable, cnnectr all fully custmizable with minimum tling cst Quick turn-arund time n new designs 2 weeks t prttypes Ecnmical pricing 8. MOUNTING Taglas flexible PCB antennas use 3M 467 duble-sided adhesive fr the mst reliable munting slutin. Ideally the Flexible PCB antenna is munted clse t the uter husing f the device t allw it t radiate utwards and receive signals withut bstructin frm internal cmpnents in the device. The antenna can be placed int a slt, screwed dwn, r affixed with duble- APN /A/MB Page 4 f 6

5 sided adhesive. Generally the rientatin f the antenna is nt critical, as lng as clearance frm metal cmpnents is maintained. 9. ENVIRONMENTAL CONSIDERATIONS Clse prximity t cmpnents r husing affects the electrical perfrmance f all antennas. When placed n a nn-cnductive area f the bard, in mst cases, there shuld be minimum clearance f 10mm in all directins frm the bard/husing fr maximum efficiency. A reductin in the efficiency f the antenna and shift in tuned frequency will be bserved if the antenna is placed clse t nisy cmpnents like switching pwer supplies, micrphnes, camera etc. Prximity effects will als have an adverse effect n the radiatin pattern f the antenna. Device husings shuld never be metal r have cnductive materials. 10. TUNING The frequencies f flexible PCB antennas with cable are easily shifted when clse t ther cmpnents r even if the cable is bent mre than 30 degrees. This phenmenn is called detuning. The antenna can als be detuned by high dielectric cnstant materials. Taglas ffers Flexible PCB antenna samples t custmers n the understanding that they be tested utside the device as a benchmark perfrmance. The actual prductin antenna will be custmized fr each custmer. This is why Taglas always ffers a tuning service t its custmers at the prttype integratin phase. We tune the antenna frequency back t the right bands fr the applicatin at ur lab. Samples are sent back t the custmer within 2 weeks f receiving the device alng with a test reprt shwing antenna perfrmance, Return Lss/VSWR, Gain, and Radiatin APN /A/MB Page 5 f 6

6 Characteristics in the custmer's device. Please cntact us fr csting fr this service. 11. CABLE & CONNECTOR Ø1.13mm diameter micr cax cable is preferred in mst GPS antenna prjects as the mst ecnmical slutin. Cable lss is nt a big factr if cable length is kept belw 150mm. The cable shuld nt be lped because it will cause frequency shifts and als create magnetic fields which will interact with the main antenna magnetic field. The cable shuld nt have a sharp bend (90 degree). The cable shuld be kept away frm emitting cmpnents such as LCD driver chips r CPUs. It is preferred t use cnnectrs n the cables fr higher reliability in cnnectin ver slder. The mst ecnmical cnnectr slutin is the IPEX line f cnnectrs which are cmpatible with Hirse industry standards U.FL and W.FL. Taglas ffers any cable and cnnectr slutin fr the integratr. Taglas als ffers the n-bard mating cnnectr and cable jumpers. APN /A/MB Page 6 f 6